This article's from last September, but -- despite Avatar -- I reckon many of its points still stand. And it's therefore excellent.

On a related note, also check out Bwana Beowulf and Coraline, cornered from the same blog. Both are further discussions of 3D, using specific films (which should be obvious) as case studies, and continue to demonstrate why this 3D malarky isn't all its cracked up to be.